Browsing by Author "Yilmaz K."

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    Prediction of ratio of mineral substitution in the production of low-clinker factored cement by artificial neural network
    (Association for Scientific Research, 2003) Canpolat F.; Yilmaz K.; Ata R.; Köse M.M.
    Artificial Neural Networks (ANN) has been widely used to solve some of the problems in science and engineering, which requires experimental analysis. Use of ANN in civil engineering applications started in late eighties. One of the important features of the ANN is its ability to learn from experience and examples and then to adapt with changing situations. Engineers often deal with incomplete and noisy data, which is one of the areas where ANN can easily be applied. Dealing with incomplete and noisy data is the conceptual stage of the design process. This paper shows practical guidelines for designing ANN for civil engineering applications. ANN is in cement industry: in the production of low-clinker factored cement, and in the derivation of composition of natural and artificial puzzolans in the production of high performance cement and concrete. By using ANN, a study to find out the optimum ratio of substitution and compression strengths was carried out.
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    Use of zeolite, coal bottom ash and fly ash as replacement materials in cement production
    (2004) Canpolat F.; Yilmaz K.; Köse M.M.; Sümer M.; Yurdusev M.A.
    In this research, the effects of zeolite, coal bottom ash and fly ash as Portland cement replacement materials on the properties of cement are investigated through three different combinations of tests. These materials are substituted for Portland cement in different proportions, and physical properties such as setting time, volume expansion, compressive strength and water consistency of the mortar are determined. Then, these physical properties are compared with those of PC 42.5. The results showed that replacement materials have some effects on the mechanical properties of the cement. The inclusion of zeolite up to the level of 15% resulted in an increase in compressive strength at early ages, but resulted in a decrease in compressive strength when used in combination with fly ash. Also, setting time was decreased when zeolite was substituted. The results obtained were compared with Turkish Standards (TS), and it was found that they are above the minimum requirements. © 2004 Published by Elsevier Ltd.
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    Sulfate resistance of mortars with and without silica fume and natural pozzolan
    (2007) Canpolat F.; Yurdusev M.A.; Targan S.; Yilmaz K.
    An investigation was carried out on the effect of sulfate attack on the sulfate durability of mortars produced with natural zeolite and silica fume having pozzolanic character. Experiments were accomplished on the standard Rilem sand and portland cement mortars where the cement was replaced by various rates of natural zeolite (Z) and silica fume (SF) separately and together. 5% sodium sulfate solution and 5% magnesium sulfate solution were 5% sulfate exposures of mortars were initiated after 28 days of lime saturated water curing, compressive strength and density were determined at the beginning of exposure and at the 2nd, 7th, 28th, 90th days. Water and solutions were renewed after each period of experimental time, 14 days. Mass changes were determined at the time of renewing the solutions. The effects of sodium sulfate solutions on the properties of mortars were related to the zeolite and silica fume ratio. It is found that zeolite and silica fume replacement had caused significant increase in sulfate durability of mortars even at the highest sulfate concentration up to 90 days of exposure. The durability to sulfate attack was obtained with silica fume replacement 5-10%, but strength loss of 10-15% can be expected. Mortars with SF and Z were damaged in magnesium sulfate solution. The compressive strengths decreased with increasing SF and Z content. The test results showed that the use of Z and SF in concrete exposed to magnesium sulfate environment is not recommended. © 2007 Taylor & Francis Group, London.
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    Breast-feeding knowledge and practices among mothers in Manisa, Turkey
    (2009) Yanikkerem E.; Tuncer R.; Yilmaz K.; Aslan M.; Karadeniz G.
    Objective: to determine breast-feeding knowledge and practices among mothers before and after an educational intervention on breast feeding. Design: cross-sectional, descriptive study using a face-to-face questionnaire. Setting: Manisa Maternity and Children's Hospital, which has Baby Friendly status. Participants: 158 women in the early postpartum period. Measurements and findings: 10.8% of women were not aware that they should offer colostrum to their babies. Only 43.7% of women commenced breast feeding within the first 30 minutes of giving birth. Prior to receiving the educational intervention, 55.7% of mothers knew how often they should feed their baby, 48.7% knew that they should breast feed their baby for two years together with additional food, although 55.1% of women did not know how to hold their breast during a feed. The mean pre-test score was 9.9 (SD 2.4; range 3-13), and the mean post-test score was 12.6 (SD 0.8; range 9-13). The difference between the mean pre- and post-test scores was statistically significant (paired t=15.3, df=157, P<0.001). Conclusion and implications for practice: given the integral role of breast feeding in improving overall community health, regular breast-feeding counselling should be offered, particularly during the pregnancy and early postpartum period. © 2007 Elsevier Ltd. All rights reserved.
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    Pediatric kidney care experience after the 2023 Türkiye earthquake
    (Oxford University Press, 2024) Bakkaloǧlu S.A.; Delibaş A.; Döven S.S.; Taner S.; Yavuz S.; Erfidan G.; Vatansever E.D.; Aynaci F.; Yilmaz K.; Taşdemir M.; Akaci O.; Akinci N.; Güven S.; Çiçek N.; Dursun I.; Keleşoǧlu E.; Sancaktar M.; Alaygut D.; Saygili S.; Yavaşcan Ö.; Yilmaz A.; Gülleroǧlu K.; Ertan P.; Demir B.K.; Poyrazoǧlu H.; Pinarbaşi S.; Gençler A.; Baştuǧ F.; Günay N.; Çeleǧen K.; Noyan A.; Parmaksiz G.; Avci B.; Çayci F.Ş.; Bayrakçi U.; Özlü S.G.; Aksoy Ö.Y.; Yel S.; Inal G.A.; Köse S.; Bayazit A.K.; Atmiş B.; Saribaş E.; Çaǧli Ç.; Tabel Y.; Elmas A.T.; Selçuk Ş.Z.; Kiliç B.D.; Kara M.A.; Büyükçelik M.; Balat A.; Tiryaki B.D.; Erdoǧdu B.; Aksu B.; Mahmudova G.; Dursun H.; Candan C.; Göknar N.; Mutlubaş F.; Çamlar S.A.; Başaran C.; Akbulut B.B.; Düzova A.; Gülhan B.; Oruç Ç.; Peru H.; Alpay H.; Türkkan Ö.N.; Gülmez R.; Çelakil M.; Doǧan K.; Bilge I.; Pehlivanoǧlu C.; Büyükkaragöz B.; Leventoǧlu E.; Alpman N.; Zeybek C.; Tülpar S.; Gülşan R.Y.Ç.; Kara A.; Gürgöze M.K.; Önder E.N.A.; Atikel Y.Ö.; Pul S.; Sönmez F.; Yildiz G.; Akman S.; Elmaci M.; Küçük N.; Yüksel S.; Kavaz A.; Nalçacioǧlu H.; Alparslan C.; Dinçel N.; Elhan A.H.; Sever L.
    Background. Two earthquakes on 6 February 2023 destroyed 10 cities in Türkiye. We report our experience with pediatric victims during these catastrophes, with a focus on crush syndrome related-acute kidney injury (Crush-AKI) and death. Method. Web-based software was prepared. Patient demographics, time under rubble (TUR), admission laboratory data, dialysis, and kidney and overall outcomes were recorded. Results. A total of 903 injured children (median age 11.62 years) were evaluated. Mean TUR was 13 h (interquartile range 32.5, max 240 h). Thirty-one of 32 patients with a TUR of > 120 h survived. The patient who was rescued after 10 days survived. Two-thirds of the patients were given 50 mEq/L sodium bicarbonate in 0.45% sodium chloride solution on admission day. Fifty-eight percent of patients were given intravenous fluid (IVF) at a volume of 2000-3000 mL/m2 body surface area (BSA), 40% at 3000-4000 mL/m2 BSA and only 2% at > 4000 mL/m2 BSA. A total of 425 patients had surgeries, and 48 suffered from major bleeding. Amputations were recorded in 96 patients. Eighty-two and 66 patients required ventilator and inotropic support, respectively. Crush-AKI developed in 314 patients (36% of all patients). In all, 189 patients were dialyzed. Age > 15 years, creatine phosphokinase (CK) =20 950 U/L, TUR =10 h and the first-day IVF volume < 3000-4000 mL/m2 BSA were associated with Crush-AKI development. Twenty-two deaths were recorded, 20 of 22 occurring in patients with Crush-AKI and within the first 4 days of admission. All patients admitted after 7 days survived. Conclusions. These are the most extensive pediatric kidney disaster data obtained after an earthquake. Serum CK level was significantly associated with Crush-AKI at the levels of > 20 950 U/L, but not with death. Adolescent age and initial IVF of less than 3000-4000 mL/m2 BSA were also associated with Crush-AKI. Given that mildly injured victims can survive longer periods in the disaster field, we suggest uninterrupted rescue activity for at least 10 days. © The Author(s) 2024.